Hydrodynamic coupling

ABSTRACT

The invention relates to a hydrodynamic coupling. Said coupling comprises a primary wheel ( 2; 2.2; 2.3 ) and a secondary wheel ( 3; 3.2; 3.3 ), which together form a toroidal working chamber ( 4; 4.2; 4.3 ), a shell ( 5; 5.2; 5.3 ), which is connected in a rotationally fixed manner to the primary wheel and surrounds the secondary wheel in the axial direction and at least partially in the radial direction, thus forming an intermediate chamber ( 6; 6.2; 6.3 ) and at least one passage ( 8; 8.2; 8.3 ) that is located in the outer radial area of the shell. The invention is characterized by the following features: a second shell ( 10; 10.2; 10.3 ) coupled in a rotationally fixed manner to the first shell and/or the primary wheel, thus forming a second intermediate chamber ( 11; 11.2; 11.3 ); the second intermediate chamber is connected to the first intermediate chamber via the passage ( 13; 13.2; 13.3 ); at least one passage in the outer radial area of the second shell, the passage or passages in the first shell and the passage or passages in the second shell being offset in relation to one another, when viewed from the peripheral direction.

[0001] The invention relates to a hydrodynamic coupling, in particularhaving the features of the preamble of claim 1.

[0002] Hydrodynamic couplings are known in different embodiments from amultitude of publications. As representative, reference is made to Voithpublication Nr. CR 277d 5.00 1000. This discloses a hydrodynamiccoupling with an integrated oil-supply arrangement. This includes aprimary wheel functioning as a pump wheel and a secondary wheel;assigned to the primary wheel is a so-called shell that is connected tothe latter in a rotationally-fixed manner and surrounds the secondarywheel in the axial extension and at least over a portion of the radialextension. The shell displays passages in the region of its outerperiphery, in particular in the region of the radially outer dimensions,which passages make possible the passing of operating medium from theshell into an additional catch shell that is coupled in arotationally-fixed manner to this shell, from which additional shell theoperating medium is conducted by means of a dynamic pressure pump in aclosed circuit during the operation of the hydrodynamic coupling. In thecase of the disconnection of the hydrodynamic coupling, by virtue of thearrangement of the passages in the shell there occurs by effect ofcentrifugal force an emptying of the toroidal work chamber and,conditioned by this, an emptying of the intermediate chamber defined bythe shell. The complete emptying thereby achieved is, however, notdesired in every case, in particular in application cases that due tofrequently alternating filling and emptying processes require a veryquick filling process in order to ensure a rapid transfer of torque.

[0003] The invention is thus based on the task of further developing,with low structural and production technology expense, a hydrodynamiccoupling of the type specified in the introduction such that duringoperation the filling via the inlet is sustained, while the outflowthrough the nozzles is ensured, and that during the standstill of thecoupling a partial filling is ensured. In this way:

[0004] the fill supply can be shortened in the case of a desired quickplacing into operation and/or

[0005] in each operating state of the hydrodynamic coupling the powertransmission between the rotor parts can be ensured.

[0006] The solution according to the invention is characterized throughthe features of claim 1. Advantageous configurations are specified inthe dependent claims.

[0007] The hydrodynamic coupling comprises a primary wheel and asecondary wheel that together form a toroidal working chamber. Connectedin a rotationally fixed manner to the primary wheel is a shell (referredto as the first shell in the following) which surrounds the secondarywheel in the axial extension and at least over a portion of the radialextension while forming an intermediate chamber. The shell displays atleast one passage that is arranged in the radially outer region of theshell. According to the invention, coupled to the shell and/or theprimary wheel is an additional shell that forms a second intermediatechamber, which is connected to the first intermediate chamber via thepassages in the first shell. The second shell likewise displays in itsradially outer region at least one passage that connects the secondintermediate chamber with the environment or with the interior of ahydrodynamic coupling formed by a housing or, in the case ofinstallation in a drive apparatus, the housing of the latter. Accordingto the invention, furthermore the passages in the first shell and thesecond shell are, when viewed in the peripheral direction, offset inrelation to each other, so that the operating medium after emerging intothe first shell is not immediately flung off into the environment, butrather must cover a particular flow route in the second intermediatechamber before it exits entirely from the hydrodynamic coupling.

[0008] According to an especially advantageous configuration, thepassages in the first shell and in the second shell are rotated 180degrees with respect to each other in the direction of the periphery.Viewed in the radial direction starting from the axis of rotation, thepassages here lie either on the same radius or the passage on the secondshell lies on a larger radius than the passage on the first shell. Basedon their spatial arrangement with respect to each other, one can alsospeak of the first shell as the inner shell and the second shell as theouter shell.

[0009] The solution according to the invention makes possible the factthat even during standstill or still during the emptying process of thehydrodynamic coupling a certain fill amount always remains in thehydrodynamic coupling, by virtue of the favorable, restricted guidancein the second, i.e. outer shell up to the exit point. This partialfilling in the standstill condition offers the advantage that, whenoperation of the hydrodynamic coupling is restarted, a certain supply ofoperating medium is already available, which supply need not first beprovided via the operating medium supply system, which can lead to atemporal delay during the filling. In particular for application casesthat are here characterized through a rapid alternation between startupof operation and shutdown of operation of the hydrodynamic coupling,this solution offers a considerable advantage in that the forces, due tothe operating medium, opposed to the startup of operation are negligiblysmall. Special filling pumps with especially high pumping capacity arenot needed.

[0010] Regarding the concrete embodiment of the second, i.e. outer shelland therewith the assignation of the intermediate chamber to the first,i.e. inner shell, and/or to the first intermediate chamber formed by theinner shell, several possibilities exist. According to the structuralspace conditions the following solutions are embraced:

[0011] a) arrangement of the second intermediate chamber, formed by thesecond or outer shell, in the axial direction next to the firstintermediate chamber formed by the first or inner shell

[0012] b) arrangement of the second, outer intermediate chamber on theoutside in the radial direction, that is, enclosing the firstintermediate chamber in the radial direction

[0013] In the first-mentioned case, the intermediate chamber extendspreferably in the radial direction into the region of the radial extentof the first intermediate chamber, that is to say, no gradation ispresent between the first and the second shells, which are arranged nextto each other. Striven for in the second case is preferably an extendingof the second intermediate chamber in the axial direction in a magnitudethat corresponds to the maximal extension of the first intermediatechamber in the axial direction. With these two solutions, a couplingconfiguration that is optimal with respect to the possible ventilationlosses can be worked out. However, it is also conceivable to realize acombination of both solutions, so that the second, outer intermediatechamber encloses, as it were, the first intermediate chamber in both theaxial and radial directions, in which both are separated by the wall ofthe first, inner shell.

[0014] The passages, in the simplest case, can be embodied asperforation bores. However, these can also be provided withcross-sectional variations, according to desired additional effects.This applies also to the alignment of the passages. These can beradially aligned or at an angle with respect to a perpendicular to therotational axis.

[0015] Regarding the concrete structural configuration, especially theconnection, of the second, outer coupling shell to the first, innercoupling shell and/or to the primary wheel, there exist a multitude ofpossibilities, which, however, lie within the normal scope of activityof the competent specialist. The outer, second intermediate chamber ishere present as a ring chamber or ring-shaped channel corresponding tothe configuration of the second shell.

[0016] In the following, the solution according to the invention isexplained with the aid of figures. These show in particular:

[0017]FIG. 1: in a schematic, greatly simplified representation, a firstembodiment of a hydrodynamic coupling designed according to theinvention with intermediate chambers arranged next to each other

[0018]FIG. 2: in a schematic, greatly simplified representation, a firstembodiment of a hydrodynamic coupling designed according to theinvention with intermediate chambers arranged radially one upon theother

[0019]FIG. 3: an embodiment with extension of the second intermediatechamber in the axial and radial directions

[0020]FIG. 4: with the aid of a simplified representation of sectionperpendicular to the axial sectional plane, the arrangement of theindividual passages

[0021]FIG. 1 illustrates, in schematic, greatly simplifiedrepresentation, a hydrodynamic coupling 1 designed according to theinvention in axial section. This comprises a primary wheel 2, which inthe traction operation functions as a pump wheel, and a secondary wheel3 functioning as a turbine wheel, which together form a toroidal workingchamber 4. Assigned to the primary wheel 2 is a shell 5, which isconnected to the primary wheel 2 in a rotationally fixed manner andencloses the secondary wheel 3 in the axial direction and at leastpartially in the radial direction while forming a first intermediatechamber 6. Provided in the region of the outer periphery 7 of the shell6 is at least one passage 8, which makes possible the passing ofoperating medium located in the first intermediate chamber 6 out of theshell 5. The passage 8 is arranged in the radially outer region 9 of theshell 5. The first intermediate chamber 6, which is bounded by the shell5, here extends in both the radial and axial directions. According tothe invention, an additional, second shell 10 is provided, which isassociated with the first shell 5 while forming an additional, secondintermediate chamber 11. The second shell 10 is attached in arotationally-fixed manner either directly to the first shell 5, ordirectly to the primary wheel 2. The second shell 10, in the embodimentaccording to FIG. 1, is assigned to the first shell 5 in the axialdirection, so that the second intermediate chamber 11 extends in boththe axial and radial directions. Here, as shown in FIG. 1, the secondshell 10 is arranged next to the first shell 5, with the passage 8 inthe first shell connecting the first intermediate chamber 6 to thesecond intermediate chamber 11. Furthermore, according to the invention,for the exit of operating medium from the second shell 10 at least onepassage 13 is provided in the region of the outer periphery 12 of thesecond shell 10; these passages 13 arranged in the second shell 10,considered in reference to the rotational axis R, are arranged in anoffset manner with respect to the passage 8 in the first shell.Preferably, the arrangement with respect to the axis of rotation occursin a mirror-image manner with respect to the passage 8 in the firstshell 5, that is to say, with an offset of approximately 180 degrees.The arrangement of the passage 13 takes place in the radially outerregion 14 of the second shell 10. In the embodiment represented in FIG.1, the two intermediate chambers—the first intermediate chamber 6 andthe second intermediate chamber 11—are arranged next to each other inthe axial direction, a separation taking place by means of the wall ofthe first shell 5.

[0022]FIG. 2 illustrates an additional embodiment of a hydrodynamiccoupling 1.2 designed according to the invention comprising a primarywheel 2.2 and a secondary wheel 3.2, which together form a toroidalworking chamber 4.2. Here too the primary wheel 2 [translators' note:should read “2.2”] is coupled to a shell 5.2 in a rotationally fixedmanner, which shell bounds a first intermediate chamber 6.2. The firstintermediate chamber here extends, in relation to the toroidal workingchamber 4.2, in both the radial and axial directions with respect to therotational axis R. Here also, provided in the region of the outerperiphery 7.2, in particular the radially outer region 9.2 of the shell5 [translators' note: should read “5.2”] is a passage 8.2. This passageconnects the first intermediate chamber 6.2 to an additionalintermediate chamber 11.2 enclosed by a second shell 10.2. The secondintermediate chamber 11.2 is here bounded by the second shell 10.2,which encloses the first shell 5.2 in the radial direction relative tothe rotational axis R and thus forms a ring-shaped intermediate chamber,namely the intermediate chamber 11.2. The two intermediate chambers—thefirst intermediate chamber 6.2 and the second intermediate chamber11.2—are thus arranged next to each other in the radial direction. Apassing of operating medium from the second intermediate chamber 11.2 tothe environment is possible via at least one passage 13.2 in the regionof the outer periphery 12.2 of the second shell 10.2. The outerperiphery 12.2 here corresponds to the radially outer region 14.2. Herelikewise, the passage 8.2 and the passage 13.2 are designed as offsetwith respect to each other, considered in the peripheral direction,preferably in an angle of 180 degrees relative to each other.

[0023]FIG. 3 illustrates a further embodiment of a hydrodynamic coupling1.3 designed according to the invention, in which the secondintermediate chamber 11.3 extends in both the axial and radialdirections next to and partially around the first intermediate chamber6.2 [translators' note: should read “6.3”]. Here too the first shell 5.2[translators' note: should read “5.3”] is coupled to the primary wheel 2[translators' note: should read “2.3”] in a rotationally fixed mannersuch that this first shell encloses the secondary wheel 3.3 in the axialand radial directions. The second intermediate chamber 11.3 is formedhere by a second shell 10.3, which is connected to the primary wheel 2.3and to the first shell 5.3 in a rotationally fixed manner such that thefirst shell 5.3 is enclosed at least partially in the axial direction aswell as in the radial direction. This means that the wall of the secondshell 11.3 extends in the axial direction next to the first shell 5.3and in the radial direction over the outer dimensions at the outerperiphery of the first shell 5.3. Here too, the arrangement of thepassages 8.3 and 13.3 takes place preferably in the region of theradially outer dimensions in each case, so that under the influence ofthe centrifugal force an optimal and rapid transport of the operatingmedium desired to be emptied can take place.

[0024] In the embodiments represented in FIGS. 1 and 2, the extension ofthe second intermediate chamber 11 or 11.2, respectively, is adapted ineach case to the extension of the first intermediate chamber 6 or 6.2,respectively. In FIG. 1, this means an extension in the radial directionanalogous to the extension of the first intermediate chamber 6, while inFIG. 2 the axial extension of the second intermediate chamber 11.2 doesnot substantially occur over the axial extension of the firstintermediate chamber 6.2. In order to avoid unnecessary losses through astepped configuration of the outer contour of the hydrodynamic coupling1, there preferably occurs a matching or laying out of the individualintermediate chambers so that steps, i.e. large, sudden changes indiameter, are avoided.

[0025]FIG. 4 illustrates, in greatly schematized representation in asectional plane perpendicular to the axial sectional plane of ahydrodynamic coupling 1.4, the arrangement of the passages 8.4 and 13.4on the individual shells 5.4 and 10.4, respectively. It is evident herethat the two passages 8.4 and 13.4 are arranged offset with respect toeach other by an angle, preferably 180 degrees, in the peripheraldirection. In order to attain a minimal fill state (the fill stateheight is here labeled with 15) [translators' note: label not visible inFIG. 4] in the standstill condition, the corresponding arrangement ofthe bores is here necessary. Upon rotation around the rotational axis,operating medium flows through the toroidal working chamber 4.4, whichmedium travels outwardly into the first shell 5.4 due to centrifugalforce, from where the operating medium, likewise due to centrifugalforce, reaches the second intermediate chamber 11.4 via the passage 8.4,from which chamber it is released via the passage 13.4 into theenvironment or into the housing, again due to centrifugal force. Thepassages are here preferably arranged on the same radius, or the passagein the second shell is arranged on a larger radius than that of thefirst shell. In order to make possible, instead of an immediate andcomplete emptying, a partial fill state in the standstill condition,which partial fill state is independent of the position of the firstshell and thus also the second shell, the operating medium is conductedfrom the first shell 5.4 via the second intermediate chamber 11.4 beforeit exits into the environment or into the housing.

REFERENCE NUMERAL LIST

[0026]1; 1.2; 1.3 hydrodynamic coupling

[0027]2; 2.2; 2.3 primary wheel

[0028]3; 3.2; 3.3 secondary wheel

[0029]4; 4.2; 4.3 toroidal working chamber

[0030]5; 5.2; 5.3 shell

[0031]6; 6.2; 6.3 first intermediate chamber

[0032]7; 7.2; 7.3 outer periphery of the first shell

[0033]8; 8.2; 8.3 passage

[0034]9; 9.2; 9.3 radially outer region

[0035]10; 10.2; 10.3 second shell

[0036]11; 11.2; 11.3 second intermediate chamber

[0037]12; 12.2; 12.3 outer periphery

[0038]13; 13.2; 13.3 passage

[0039]14; 14.2; 14.3 radially outer region

[0040]15; 15.2; 15.3 fill state height [translators' note: numeral doesnot appear on drawings]

[0041] R rotational axis

1. Hydrodynamic coupling (1; 1.2; 1.3); 1.1 having a primary wheel (2;2.2; 2.3) and a secondary wheel (3; 3.2; 3.3), which together form atoroidal working chamber (4; 4.2; 4.3); 1.2 having a shell (5; 5.2; 5.3)that is connected to the primary wheel (2; 2.2; 2.3) in a rotationallyfixed manner and encloses the secondary wheel (3; 3.2; 3.3) in the axialdirection and at least partially in the radial direction while formingan intermediate chamber (6; 6.2; 6.3); 1.3 having at least one passage(8; 8.2; 8.3) that is arranged in the radially outer region (9; 9.2;9.3) of the shell (5; 5.2; 5.3); characterized through the followingfeatures: 1.4 having an additional, second shell (10; 10.2; 10.3)coupled to the shell (5; 5.2; 5.3) and/or to the primary wheel (2; 2.2;2.3) in a rotationally fixed manner while forming an additional, secondintermediate chamber (11; 11.2; 11.3); 1.5 the second intermediatechamber (11; 11.2; 11.3) is connected to the first intermediate chamber(6; 6.2; 6.3) via the passage or passages (8; 8.2; 8.3); 1.6 having atleast one passage (13; 13.2; 13.3) in the radially outer region (14;14.2; 14.3) of the second shell (10; 10.2; 10.3), the passage orpassages (8; 8.2; 8.3) in the first shell (5; 5.2; 5.3) and the passageor passages (13; 13.2; 13.3) of the second shell (10; 10.2; 10.3) beingoffset in relation to one another, when viewed from the peripheraldirection.
 2. Hydrodynamic coupling (1; 1.2; 1.3) according to claim 1,characterized in that the passage or passages (8; 8.2; 8.3) of the firstshell (5; 5.2; 5.3) and the passage or passages (13; 13.2; 13.3) of thesecond shell (10; 10.2; 10.3) are arranged offset in relation to oneanother by an angle of 180 degrees, when viewed from the peripheraldirection.
 3. Hydrodynamic coupling (1) according to one of the claims 1or 2, characterized in that the second intermediate chamber (11) isarranged next to the first intermediate chamber (6) in the axialdirection.
 4. Hydrodynamic coupling (1) according to claim 3,characterized in that the second intermediate chamber (11) displays anextension in the radial direction that is equal to or less than theradial extension of the first intermediate chamber (6).
 5. Hydrodynamiccoupling (1) according to one of the claims 3 or 4, characterized inthat the passage or passages (8) in the first shell (5) and the passageor passages (13) in the second shell (10) are arranged, in each case, onradii or diameters having the same dimensions, in relation to the axisof rotation R.
 6. Hydrodynamic coupling (1.2) according to one of theclaims 1 or 2, characterized in that the second intermediate chamber(10.2) encloses the first intermediate chamber (6.2) in the radialdirection.
 7. Hydrodynamic coupling (1.2) according to claim 6,characterized in that the extension of the second intermediate chamber(11.2) in the axial direction is equal to or less than the axialextension of the first intermediate chamber (6.2).
 8. Hydrodynamiccoupling (1.2) according to one of the claims 6 or 7, characterized inthat the passage or passages (13.2) in the second shell (10.2) is/arearranged on a larger diameter than the passage or passages (8.2) of thefirst shell (5.2)
 9. Hydrodynamic coupling (1.3) according to one of theclaims 1 or 2, characterized in that the second intermediate chamber(11.3) at least partially encloses the first intermediate chamber (6.3)in both the axial and radial directions, and that the passage orpassages (13.3) in the second shell (10.3) have a diameter that, withrespect to its dimensions, is equal to or greater than that of thepassage or passages (8.3) in the first shell (5.3).
 10. Hydrodynamiccoupling according to one of the claims 1 through 9, characterized inthat the passage or passages (8; 8.2; 8.3) in the first shell (5; 5.2;5.3) and the passage or passages (13; 13.2; 13.3) of the second shell(10; 10.2; 10.3) are offset in relation to one another at an angle inthe range of 90° to 270°, when viewed from the peripheral direction.